The molecule programmed death-1 (PD-1) is a critical element in the negative regulation of cellular immune responses. Blockage of the interaction between PD-1 and its ligand PD-L1 has... Show more The molecule programmed death-1 (PD-1) is a critical element in the negative regulation of cellular immune responses. Blockage of the interaction between PD-1 and its ligand PD-L1 has emerged as a promising therapeutic approach for several cancers underlining the importance of this molecule. Expression of PD-1 has been used as valuable marker in the differentiation between different types of T-cell non-Hodgkin lymphoma. The studies presented in this thesis are focused on the expression of PD-1 in primary cutaneous T-cell lymphomas and cutaneous B-cell lymphomas in order to determine whether expression of PD-1 might also be a useful marker in the diagnosis of different types of cutaneous lymphoma. Differentiation between the different types of cutaneous lymphoma is extremely important, as they have a completely different prognosis and require different types of treatment. The investigations in this thesis provide a detailed description of the differential expression of PD-1 in distinct types of cutaneous lymphomas, revealing that PD-1 has the potential of a diagnostic biomarker, especially for Sézary syndrome and primary cutaneous small/medium-sized pleomorphic T cell lymphoma. The overall conclusion is that PD-1 may serve as a suitable adjunct to improve diagnosis, and may enable better classification of provisionally classified cutaneous lymphoma entities. Show less
